Sleeping bag how warm for winter?

[Ent]

Content removed by poster

[Nuts]

Something to watch for also;

I have noticed that most manufacturers ultralight bags (ie. also usually the bags at the top end (850+) of their range/price) achieve weight savings by reducing dimensions. You may get a super-light bag, it may be warm and efficient but check the measurements or you'll feel like a 'banger in a bun'.

Corvus, i see those ethical claims. My point was that I was just wondering, still, how the gear is more expensive.There are US based companies offering similar moral claims (and even recycled products), but the bags are mostly cheaper. Looks like a nice bag anyhow.

At the moment some of the gear is so cheap, it would be possible to try a couple of different manufacturers offerings and sell them on until you found one 'suitable' as it really is personal preference and circumstances (which makes any rating system a very general 'guide'). Proof is in the pud' as they say.

[corvus]

G'day Nuts,
I thank you for your comments re US suppliers but are they actually manufactured in the US or are they like WE-S2S outsourcing their manufacturing in Asia.
corvus

[tasadam]

An interesting discussion indeed.
I feel from reading that there is one big problem - the "rating" system.
Perhaps we need a recognised Australian Standard, or even better, international standard, for sleeping bags.

Shouldn't be hard to work out -
Get a manequin with a soft flexible waterproof outer and a hollow inner, built with a heating element in the middle and it being filled with approx 75 kilos of water. Have a heat conductive tube running through the manequin and pump air through from the immediate environment at roughly the average amount of air breathed by a sleeping person, and a pump to circulate the water around in the manequin at roughly the flow of blood produced from the heart of an average sleeping person.

Place the manequin in an environment of say 16 degrees celcius.
Bring the temperature of the manequin internals up to 37.5 degrees or whatever normal body temp is.
Stabilise the temperature and set the heating element thermostat to that setting so the amount of power given to the element remains constant.

Now we have our benchmark (though the numbers are out of my head and may need refining).

Stick the manequin in a whole heap of sleeping bags and set the temperature. Control the outside temperature, probably by doing the testing in a big refrigerator room.
Do it on a well insulated surface such as 10 of the best thermarests or similar so there are no external factors draining temperature.

See which bags maintain manequin temperature and therefore should maintain body temperature.
Rate the bags.

Submit the data and associated testing method used to the Australian Standards and International Standards associations.
Perhaps enlist (ask) a university somewhere to help with this.

At least it will take the guesswork out of the rating system and we can relate the numbers to something.

Anyone interested in taking something like this on board? Or, another idea of mine gone begging because I come up with ideas and don't bother seeing them through...

[corvus]

The University of Leeds do the test rating for Tundra Bags so pehaps you should contact them tasadam

[Nuts]

Perhaps we could suggest something to the mythbusters

I think this thread is becoming a bit confusing. All I can really add is that the comfort rating under the european standards is a reliable guide for most people (regardless of what rating is actually advertised/ printed on the bag). The bags will reach the transition rating only with additional layers or if you are a very warm sleeper.

It suddenly makes many bags seem less attractive at first glance but in my experience it is a good reliable guide. It would be a costly mistake(unless thats your preference) to assume that the bags major OS companies are any less than what we are used to seeing here. From the (former) locally produced bags my experience is that they are advertised with this 'comfort' rating as their standard. That is- you will be buying the same product either way, just takes a bit more research! More like having (what we know as a ) -7 OP bag which also has more data giving a better explaination for the range of buyers- a better system in my opinion.

Corvus, the brand I buy say they only use manufacturers who meet ethical standards, they are mostly produced in China/Vietnam. If it is more environmental ethics that yank your chain, they also produce a recycled bag (95%). This side of things has never been a big issue for me personally- I don't believe half of what they say anyhoot! Even if so i wonder that in many places people would rather work for a pittance than not work. Also on the enviro. side- The things do several world trips getting here, the situation seems crazy and the impact of all this stuff being moved must be enormous. I admire the stated ethics of those folks you are buying your bag off- one step better would be to produce the things (from scratch) here in Oz (Heads up OP)- using our technology to advantage and making (not only socially ethical) but environmentally minimal impact!

[corvus]

Nuts no critizium of your source just an observation that costs are cheaper in Asia and USA that may be why prices from Europe are a bit higher .
corvus

[corvus]

Like the big kid that I am I just had to try out the new bag however being as crook as a dog with two sore eyes and with both a gutser(doc gave it some fancy name) and a lurgy I chickened out and slept on the Lounge room floor with a Pro lite 4 under me a silk liner and thin cotton nightshirt (don't laugh they are damn comfortable) in my never get below 15% household .
Result was this bag performed better than expected and only in the coldest hour b4 dawn did I think that a pair of socks would be nice ,had to keep it unzipped with one arm out regularly and I did build up a sweat .
As stated b4 I will be testing this bag out in July in a tent on a mountain but at this stage I feel that regardless of Maker if you want a GOOD bag choose 850+ loft down.
It has taken me 50 years to be in a position to own really good gear and My Kapok filled waterproof base sleeping bag I got in 1957 was in my opinion the best and I can remember my Dad saying that he could only afford either a good pack or a good S/bag ,what did I choose well being a gear freak I wanted both so I had to put up with crapacious stuff for a few years till I got a paper round type job and replaced iffy with ex army goodish type stuff ,my Bergen Pack was the envy of my mates and the S/bag was the bees knees,gees we even ended up with a Gilwell Hike Tent with a floor (the old Vango Company made them)
Enough already of this reminiscence the tears are clogging my keyboard
So get the best you can afford at the time and build up.
corvus

[Nick S]

I have recently done a lot of research into this topic as I am a very cold sleeper . . . . . .

One aspect of using sleeping bags that has not come up yet is the fact that the quality of the bag is in its ability to control heat loss from your body. If you get into a super warm sleeping bag and you have been shivering around your fuel stove in a howling southerly, your peripheral temperatures are likely to be significantly lower than than core temperature. When in your bag, your hands and feet will only come up to core temperature as your body produces enough heat to restore the normal temperature of your extremities. We all can vary in our metabolic rate and how much hear we produce at "idle", so folks who say they are "cold sleepers" need to kick start their heat production at the time they hop into their sleeping bag. I always thought I was a "cold sleeper" and continue to use my 1968 Everest Mummy bag for all seasons, but have found over the years that if I am not rugged up enough and warm enough before I get into my bag, I can lay there all night with cold feet. My simple fix for this is to do a few minutes of jogging on the spot or star jumps etc to get the muscles working and pulse racing then quickly hop into my sleeping bag. That bit of extra heat on bag entry can make an amazing difference to the initial warm up of the inside of the bag, and a very comfortable nights sleep. Try it next time you are camping in the cold and see what difference it makes.

This is my experience exactly, I would say I'm a cold sleeper, but If I've just eaten or jumped around a bit before jumping in the sleeping bag, then I get that initial production of heat that means I'm not shivering for 20min to warm my hands and feet. Maybe it's more of a circulation problem then just a body core/cold sleeper thing. I've recently brought a Large OP Winter Lite 750, which I've yet to put to real test, but am looking forward to not waking up at 4am shivering..

Regarding a previous post; My understanding is that women can have a lower basal metabolic rate, (or the amount of energy used during rest) than males even given weight differences, as in general males have a greater muscle mass and a lower body fat percentage, which is one of the determinants of BMR. Therefore they are more likely to be colder sleepers.

[sarge]

Hi just an update on my sleeping bag purchase. I had planned to get a one planet bag but because of some budgeting restraints ended up with a Western Mountaineering Apache Dryloft instead. This bag sells for $999 at Paddy Pallin which is an absolute rip off because you can buy it online for less than half the price from US (although I managed one for $300 on ebay).

I tried it last weekend and can say it is absolutely the warmest and most comfortable bag I have ever slept in. It weighs just over the 1kg mark (which is light for me!) and according to the US manufacturer is good for -17c. The 'Dryloft' is quite amazing as it traps the air and literally 'inflates' when you take it out of the stuff sack. It feels like your sleeping wrapped up in a doona! Once in the stuff sack it squashes down to about 25cm so hardly takes up any room.

Definitely recommend to cold sleepers if you can get one on the cheap.....

[MichaelfromQLD]

I own a Fairydown Viper with Dryloft outer. I dont have any problem with packing it down into a stuff sack.
I have also read where people say that its hard to pack and that you need to unzip it stuff it into the bag. I totally disagree.
Yes, I have to be careful and start with the foot end first, but all air squeezes out through that big hole int the top. I dont use the compress the bag as much as I could because I have plenty of room in my pack and I think that squashing the down more than you need to is going to be detrimental over a period.
I have a dryloft bag and a pertex bag, I only ever use the dryloft these days, mainly because it is a bit lighter and I can dont need to be as careful in my tent.

Roger

I also own this bag (windstopper shell).

I agree, you must be careful and start at the foot end when packing, compressing as you go. There is no need to apply extra compression once it is in it's stuff sack. It does take a couple of minutes to pack.

I've been warm in heavy (-5) frosts in my tent with this bag and base layer thermals, but I've also been cold in a draughty hut at +1 and raining - mostly due to cold air entering in the neck - later that same night I woke up in a sweat.

My conclusions are:
my tent (salewa sierra leone) is a warmer place to sleep than a hut
a neck muff thingy to stop cold air getting inside your bag is highly valuable
There are more important factors to a good nights sleep than getting the perfect sleeping bag, so long as it's appropriate.
700g of good quality down should be enough for most conditions so long as it's kept dry.
Down boosters and bivy bags inside tents are great ways of extending the bags useable range.

[MichaelfromQLD]

Sorry guys, hadn't read through the entire post.

Love the mannequin idea, but a the pumps, etc, overcomplicates things. Convection currents will distribute the heat.

First, calibration must be made using a set of identical sleeping bags and a group of human subjects of varying ages, sizes, fitness and gender. Determine the minimum comfort level for each subject in the bag and create average (ideally this will be repeated using a large number of subjects).

Using an internal probe thermometer, pre-heat mannequin or other heat resevoir to 37.5 and record profile of reducing temperature over time at the pre-determined temperature. Select a level (eg temperature after 2 hours or 33 degrees) to use as cut-off. Time and heat loss levels must both be significant and heat resevoirs must be uniform.

Bags must retain the resevoir's heat above set temperature for specified time to pass.

As an aside, I actually own the fairydown COBRA not the viper, i'll check later for specs

[Son of a Beach]

Love the mannequin idea, but a the pumps, etc, overcomplicates things.

Is it just me, or did it take anyone else a few moments to remember what he was actually referring to from earlier in this topic?

[alliecat]

Hi just an update on my sleeping bag purchase. I had planned to get a one planet bag but because of some budgeting restraints ended up with a Western Mountaineering Apache Dryloft instead. This bag sells for $999 at Paddy Pallin which is an absolute rip off because you can buy it online for less than half the price from US (although I managed one for $300 on ebay).

Just FYI - Western Mountaineering have contracts with their retailers that forbid them from selling outside the US, giving Paddy Pallin an effective monoopoly on their products in Australia. You were lucky to find a WM bag on ebay because WM have been known to have auctions pulled because of their "distribution policy". I've written to WM complaining about this and received no reply. I guess this "proudly American" company (it says so on their web site) doesn't believe in the free market...

[sarge]

Just FYI - Western Mountaineering have contracts with their retailers that forbid them from selling outside the US, giving Paddy Pallin an effective monoopoly on their products in Australia. You were lucky to find a WM bag on ebay because WM have been known to have auctions pulled because of their "distribution policy". I've written to WM complaining about this and received no reply. I guess this "proudly American" company (it says so on their web site) doesn't believe in the free market...

Wow that explains a lot. the guy I bought it from in the US was amazed that it sells for so much here. I would be surprised if Paddy Pallin sells a lot of them at that price....

[tim]

Hey all,

I just did a week on the main range in Kosciuszko NP, using my One Planet Epic Bush-lite Super, which is supposedly comfort rated down to -17. Last time I used this bag was in the hut at Lake Vera, which was super-heated by a bunch of schoolboys who carried in a bunch of metho for the purpose. As such, i had shaken a fair percentage of the down fill to the under side of my bag, making it significantly less warm that it might be otherwise.

I soon remebered doing that when I found a colder (and empty) patch on my chest sleeping in a snow cave on the first night out in KNP, but was still plenty warm enough, even sleeping la natural. I also spent a few nights in a tent on the same trip, which was significantly colder, but was still comfy after putting my thermals back on, noting that I was too slack to bother re-distributing the down correctly and slept with damp socks in my armpits each night. No complaints about the warmth of the bag, then. However, I have absolutely no faith in the water-repelling abilties of the Epic fabric outer, and as such didnt sleep without a bivvy the whole trip, snowcave or tent.

I also found that my (new) Thermarest Pro-lite 3 (i think - full length, orange, pretty small) is not really substanial enough to keep my boney behind off the snow, and so I had to use either my closed-cell sit pad or a some fleece to keep my butt warm...but my mate had the same mat, and had no such drama. In future, at least for snow trips, I think I will stick to closed-cell foam - more bang for your buck, and less crampon kill-able.

Cheers